Antifreeze compound



Patented Apr. 28, i936 ANTIFREEZE COMPOUND Arthur Eichengriin, Charlottenburg, assignor to Celanese Corporation of corporation of Delaware No Drawing. Application October 19, 1933, Serial No. 694,347. In Germany December 23, 1932 4 Claims. (Cl. 252-5) Germany, America, a

chlorides that parts of the radiators or gas wherein it is exposed to low temperatures. of any prior substances 5 An obJect of my invention is to provide ant1- used for this purpose, inasmuc as sure protecfreeze compounds that are more effective and tion against fr ezing can be btain d by mp 0yuseful than those previously employed. A furmg such salts in concentrations considerably less ther ob ect of my invention is to avoid or dethan that required of substances previously used crease the danger of freezing of water or other for this purpose. liquid that is employed under such condition Thus water used in radiators or gas apparatus, that freezing of the same is liable to occur by etc. containing salts of nitrous acid in the above incorporating a metallic nitrite therein Other mentioned proportions of 1 2 remain liquid at ob ects of my invention will appear from the temperatures s o as 0 C- Even in the following detailed d cr ti proportions of 1:7 1 e a solution of concen- 15 As is known, water used for the cooling of entration, the solution merely becomes pasty gmes of automobiles and water used as seals in (through the formation of ice crystals) and does gas holders or in gas conveying apparatus and not lose its usefulness at atemperature of C., conduits, can be protected against freezing by While or examp e glycol and even alcohol at 15% the addition of suitable substances to lower the ent a n w he m phenomenon at 20 freezing point of the same, 15 C. and almost freeze at 10 C. and come substances essentially used for this purp e y freeze at 15 C. pose are organic liquids, especially simple d e superiority of the sal s of nitrous acid as polyhydrlc alcohols and their derivatives Of an anti-freeze 1S evident, S ce a S0luti0n these, the monohydric alcohols, methyl alcohol 0f the a e y be used In o h mpe ate and ethyl alcohol are by far t t efie t ve climates (while solutions of 33 to 40% concen- However thei us is not econo i l since t tration of other substances are prescribed) and rapidly evaporate in whole or in part from th even for use in arctic climates a solution of 33% hot water used for cooling the internal combusconcentration, 1. the P po o 1 part Of tion engine, with the result that safe protection a to 2 D t Water, 8 flifl against freezing, especially at very low tempera-- The water soluble nitrites in general are useful tures, cannot be attained with them and per odic for the present invention. Calcium nitrite is the replenishment is necessary. most efiective, sodium nitrite or a mixture of Of the polyhydric alcohols, such as glycol and these two salts is somewhat less effective. Exglycerine, glycerine has but a slight anti-freeze amples of other suitable metallic mtrites are po 35 eifect and is quite ineffective at even slightly retassium nitrite and barium nitrite. Because of duced temperatures. Glycol and its derivatives this, any desir d c r i n-p v n n 0r retard are more effective, but still at low temperatures ing Substances ay e added to the anti-freeze they must be used in solutions of very high consalts without danger of precipitation and concentrations, in which they present a disadvantage sequent reductlon of their effectiveness E amof forming solutions of greatly increased viscosity P195 of 051011 eventmg retardmg Their effect in normal concentration, say in the pounds that t be added are qulck hme proportion f 1: 3 is shg slaked lime, caustic soda solution caustic potash,

For instance, in the German Patent 468,917; the carbonates of calcium Sodium or potassium, the freezing limit of 17.5 c. is given for the mmdlum Pmsphate, saccharateeta With the proper selection of the corrosion premonomethyl ether of glycol, while according to o venting substances, attack upon metals, especially German Patent 469,222, at 24.2 C. a solution iron cop per and Z1110, may be safely prevented 9 concentration as hlgh as must be used with small quantities of the same. in the case of butylene glycol. If desired, the salts of nitrous acid may be 50 Inorganic compounds have heretofore not been und suitable, since on the one hand their eilect and they crystallize out upon cooling, and on the )ther hand, they consist mainly of metallic oflered for sale in cheap pasteboard packages, while the liquid anti-freeze compounds are limited to careful and expensive packing.

Since solutions of the nitrites remain liquid at low temperatures, these may be employed for the thawing of ice or snow. us by injecting, spraying or pouring the nitrites of their solutions into half frozen gas pipes or onto various wood or metallic apparatus, containers, or parts that have become covered or clogged with ice, their mobility and useiulness may be restored in an emergency.

It is to be understood that the foregoing detailed description is given merely by way of illustration and that many variations may be made therein without departing from the spirit oi my invention.

Having described my invention, what I desire and claim to secure by Letters Patent is:

1. The method 01 effecting heat transfer in a which comprises circulating through said systemtan aqueous solution containing a salt of nitrous acid in sufllcient proportion to lower the freezing point of the solution substantially below the freezing point of water.

2. The method of effecting heat transfer in a cooling system, which comprises circulating through said system an aqueous solution containpoint or the solution substantially below the freezing point of water.

2. The method of efiecting heat transfer in a which comprises circulating through said system an aqueous solution containing calcium'nitrite in suiiicient proportion to lower the freezing point of the solution substantially below the freezing point of water.

4. An anti-freeze composition containingfan aqueous solution of a salt of nitrous acid and trisodium phosphate.

ARTHUR EIcHENGRiiN.

mg sodium nitrite in suflicient proportion to lower t the freezing 

